Cooking with steam is becoming more and more popular. Meanwhile, quite a number of different systems that allow foods and comestibles to be heated and cooked using steam are known in practical applications and the literature.
Document EP 1 108 384 B1 describes a household appliance for steam cooking under atmospheric pressure, which is designed in the manner of the long-known conventional household ranges that use convection and/or infrared heaters. The aforementioned steam-cooking appliance has a housing having an oven chamber disposed therein. Cooking containers for holding the food to be cooked can be inserted at various levels in corresponding guide tracks of the oven chamber. The cooking containers used here are in the form of open pans. The appliance also has a water reservoir for storing water and a steam generator in which the water is heated to steam. The steam is then introduced into the oven chamber, where it comes directly into contact with the food to be cooked. A suitable control system and a temperature sensor disposed in the cooking chamber are used to control the supply of steam, i.e., to control the steam-cooking process.
Steam cooking appliances of the type described above produce excellent results in terms of the quality of the foods processed therein, but they have the disadvantage of requiring a complex housing design, which is why they can be expensive. Moreover, an appliance of this type requires a corresponding amount of space to be available in the kitchen.
Document DE 41 16 425 A1 describes a steam cooking appliance in which the food to be cooked can be heated both by conventional heating systems, such as top heat and bottom heat, and by supplying steam. The primary point of that appliance is to bring the steam generated in a steam generator to a temperature above 100° C. using a controllable steam superheater before the steam is introduced into the cooking chamber or into a closed cooking container. The intention of this is to allow for cooking at high temperatures in order, for example, to achieve a browning effect on the food to be cooked.
That prior publication describes the use of a closed cooking container including a food pan and a lid. In order to carry out the steam cooking operation, the cooking container is placed on a support device in the oven chamber of the range and must be connected to a flexible steam conduit, so that the steam can be introduced into the cooking container therethrough. The flexible supply conduit is connected to the steam generator device via a steam connection coupling in the door of the appliance and further conduits running in the housing.
A steam cooking appliance in which two-part closed cooking containers are used is also known from U.S. Pat. No. 4,655,192. A plurality of cooking containers can be disposed one above the other. Each cooking container is supplied with steam by a separate steam generator, the steam being introduced into the interior of the cooking container through a nozzle.
The designs according to DE 41 16 425 A1 and U.S. Pat. No. 4,655,192 allow a plurality of cooking containers to be placed in the cooking chamber of these appliances and to be independently supplied with steam via a steam supply conduit. However, they have the disadvantage that no provision is made to allow excess steam, and steam that is too cold, to be discharged to the outside, if necessary.
In these designs, the excess steam would only be able to escape when, after sufficient pressure has built up, the lid of the cooking container lifts off, so that excess air can escape from the cooking container, just as when cooking with a normal cooking pot on a cooktop burner. The disadvantage here is that the repeated lifting off of the lid produces the known fluttering or rattling noises and, moreover, that food to be cooked may escape from the container during this process. Furthermore, appliances of this design do not allow for a precisely controlled and regulated steam cooking process because there is no temperature control.
Furthermore, these appliances have an overall complex design because, in addition, they work with the assistance of conventional heating and always require an interior housing in which to place the food cooking containers.
As against this, steam cooking appliances have recently come onto the market that are very simple in design. These appliances only have a base which accommodates the steam generator and the control system thereof. The cooking containers for the food to be cooked are stackable one above the other and have openings in the base and lid parts for passing the steam therethrough. The steam generated in the base portion of the appliance is passed through the cooking containers from bottom to top, the excess steam being able to escape in the upper lid area.
These appliances are simple in design and inexpensive to manufacture, but it is not possible to achieve controlled cooking results of good quality using these appliances. For the reason alone that the steam must travel a long distance from the bottom cooking container to the top cooking container, passing over the foods located therein, proper cooking is hardly possible at the upper levels. Generally, the cooking containers then have to be rearranged here in order to allow the foods from the higher levels to cook further.